Various sensor devices have been used for various technology fields, and in order to convert a sensor measurement value into a digital signal, an analog-digital converter (ADC) is required.
A pulse width modulation technology (a method using a pulse width modulator), which is one of ADC technologies according to the related art, has several advantages. However, since a pulse width may not be increased when being implemented in a chip, it is difficult to increase resolution. That is, a value of a capacitor is decreased to implement the pulse width modulation technology in a miniature chip, wherein if amplitude of a charged current is excessively decreased to increase the pulse width, the current becomes sensitive to noise. Therefore, it is also impossible to decrease a value of the current to a predetermined value or less. As a result, the pulse width may not be increased to a predetermined value or more, and it is also difficult to increase the resolution.